title: Immunisation of pigs with killed cultures of Streptococcus suis type 2.
abstract: Ten intravenous inoculations of 10(10) formalin-killed pathogenic Streptococcus suis type 2 stimulated detectable levels of opsonic antibody and a strong protective response against intravenous challenge with 10(9) viable S suis type 2 of the same strain. Heat-killed organisms did not stimulate a protective response, even though the type-specific antigen was intact and opsonic antibodies were induced. When the number of formalin-killed organisms in the inoculum was increased 10-fold, one inoculation was insufficient to stimulate a protective response, but two inoculations protected pigs against intravenous challenge with live, pathogenic organisms. Four-hour and overnight cultures were equally immunogenic, and the response was not enhanced by either Freund's incomplete adjuvant or aluminium hydroxide gel adjuvant.
authors.affiliation: University of Cambridge, Department of Clinical Veterinary Medicine.
authors.forename: M E
authors.initials: ME
authors.lastname: Holt
authors.forename: M R
authors.initials: MR
authors.lastname: Enright
authors.forename: T J
authors.initials: TJ
authors.lastname: Alexander
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D001428:Bacterial Vaccines / Q000276:immunology*; D001831:Body Temperature; D009895:Opsonin Proteins; D013290:Streptococcal Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D013291:Streptococcus / Q000276:immunology*; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000517:prevention & control*; D014611:Vaccination / Q000662:veterinary; D015164:Vaccines, Inactivated / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D009895:Opsonin Proteins; D015164:Vaccines, Inactivated